According to my knowledge 3~8% KD is good. But I don't know exactly about it. If we target top position in Google, what is the best keyword density? If we increase KD without exceeding required limit, how to affect it for optimization?
Tweaking your keyword density won't have much affect on your search engine rankings. It is not an important enough ranking factor. You could have the optimal keyword density, but if you don't have better backlinks than the sites ranking above you, then it doesn't mean shit. Don't obsess over keyword density. It is a waste of time. Just ensure that you don't look spammy by having a very high keyword density. Write your content for your visitors instead of search engine spiders. If you want better rankings, it will mostly come down to getting better backlinks.
I have found that if you a keyword density for a specific keyword phrase between the 2-3% range you will be ok. It is better to have more instances of the keyword on the page up to a point. You want to have more exact matches but in order to keep the density low you have to increase the volume of text on the page.
Bit of a varied range of opinions there. I read recently 2-5%, much higher and you start looking spammy also.
I'm beginning to believe you on this one. I optimized my Squidoo Lens with a 2.5% keyword density. My keyword in quotes had 1900 monthly searches and only 32,000 results. Low competition. Ideal. But... 3 Days later when my site got indexed...it was on page 4. Yahoo Site explorer told me I had 645 inbound links to my Lens. Not enough to beat the person in position 1 who had 2710 inbound links. But I should have beat the guy in position 2 who had only 21 links. So you're right. It's not about keyword density. It's not about numbers either. It's about the relevancy of the links and the importance of the links that link to you. And ultimately about the content and how it's able to convert your visitors.
Ezine articles forces publishers to use 2% or less. Have you seen how those articles rank in Google? Keyword density is the smaller among other ranking factors: - Title or H1 header - Backlinks + age of site = PR. Basicly... - Constant updates. Either from your homepage or blog or forum within the same domain. - If you can't add a simple forum to your site to generate free content and invite Googlebot back multiple times then You might aswell stick to offline advertising. - Keep Google coming back to your site by updating content and the backlinks will follow. Other people will link to your site or forum posts and build your links for you "naturally". If you do this you can pretty much rank high in any search engine for the keyword of your choice. So in conclusion I would suggest a keyword density hovering in the range of 2%, but feel free to use 5% as I have never seen proof of that exact number.
Goodness, I wish someone would please sticky this blog post - Keyword Density has NO relevance to search engine position
You can use 3 to 7% for major keywords. For minor keywords you can have a density of 1 to 2%. The places you can put your keywords are: 1) The TITLE tags 2) The META description 3) The META keywords tags 4) In the alt attributes of images 5) Throughout the body text of your pages 6) In the H1 or H2 tags on your pages
I'm sorry to point this out, but both of the sites in your signature don't rank in the first 15 pages on Google.com for your keyphrases..... I wouldn't be putting too much trust in their answers. Trust me, keyword density doesn't matter at all. Get your keyphrase in the title tag, h1 tag and at least once in the main body of the text and you'll be fine... then just build IBLs. I'm not flaming, I'm simply trying to give honest and accurate answers and it's hard when you have people claiming (incorrectly) the exact opposite.